Sending message to some of the clients subscribed on same topic in MQTT

Question

Is it possible to that two clients are subscribed to same topic in MQTT broker. And based on authorization, some of the massages are sent to one client and not other (subscribed on same topic).

Answer 1

No

Any number of clients can be subscribed to a given topic, but you can not limit which of those clients can receive messages on that topic on a per message basis. It is all the topic or none.